Weidmueller Heavy Duty Connectors

Technical data
Electromagnetic compatibility (EMC)
Overview
A
Many interfaces require the use of a connector that is
EMC-compliant.
What is meant by the phrase EMC-compliant?
Electro-magnetic compatibility (EMC) refers to the
ability of electrical equipment to function satisfactorily
in its electromagnetic environment without introducing
intolerable electromagnetic disturbances to anything in that
environment.
(DIN VDE 0870). An electrical component or electrical
equipment is considered to be compatible when their
emissions and sensitivity levels are within a tolerable range
(i.e., when there is sufficient interference immunity).
The basics
There are several types of measurements that can be used
to determine the effectiveness of a cable shield. The method
used here is the KS 04 B measurement from VG 95 373‐41
“Electromagnetic compatibility of devices – methods for
measuring shielded cable and shielded protective cable
hoses”. This method enables the quality of the shield to
be evaluated. It also assesses the influence of the contact
points of the shielding braid as well as the male and female
plug components.
A standardised test cable with a length of one metre is used.
This, and the fact that this measurement is carried out in a
50-ohm system which does not take the actual line
impedance into account, leads to characteristic resonance
effects. This means that this measurement process only
delivers meaningful results up to a frequency of 30 to
100 MHz. It is, however, well suited for evaluating and
comparing the effectiveness of various shielding and shieldcontacting
methods. It does not deliver an absolute value
that would enable the limiting of voltages coupled in a
cable, using an imposed HF electromagnetic field. The user
should always consider the measurement results relative to
the laboratory operational situation. Your actual, real-world
shield attenuation values will normally be less than the
values achieved in the lab because of different cable lengths,
impedance behaviour and non-optimal earthing.
Testing methods
The method applied does not use the normative tri-axial
measuring platform, but instead uses an aluminium plate
(with dimensions 500 x 380 x 10 mm). This plate serves
as the test’s reference earth. HF sockets (N-standard) are
mounted on two standing angular panels and are used to
connect the measuring device. The flange along with the
plug are mounted to one of the angular panels.
The limit value of the shield attenuation Sa is
f < 1 MHz: 60 dB
1 MHz < f < 100 MHz: 60 – 30 dB with15 dB per decreasing
decade f = 100 MHz: 30 dB
According to VG 95373-41, a frequency range up to 30 MHz
is specified for the measurement process. However the
range can be extended to about 100 MHz for information
purposes.
The insertion loss as of the test object is determined by
the relationship between the voltage on the interior wire
and the supplied voltage. The VG95373-41 also refers
to the insertion loss as the shield attenuation factor.
The relationship between insertion loss as and coupling
resistance Zk is characterised as follows:
Insertion loss: a s ≈ 20 l g 50 Ω / | Z k | in dB
Coupling resistance: Z k ≈ 50 Ω x 10 a s / 20 in Ω
According to VG 95373-41, this relationship has sufficient
precision when Z k < 500 mΩ.
A.30 2028800000